There is a limiter, but it's not a switch type limiter. I'm no electrician but I was just studying the steps helping a friend with his. Basically once the steps reach the stop the motor will draw more amps to try and keep pushing them, and the control board senses the amp draw and shuts off the motor. Sounds like that could have gone bad. However, if the gears are grinding my guess is they've already been damaged.
2021 Nexus Viper 27V. Class B+
2019 Ford Ranger 4x4